Afternoon highs

Not sure if you had a problem posting, or if you only intended to post the subject, Bbach, but if you give us some more details like your insulin regimen and diet, etc, perhaps we can help!

Yeah I had problems posting. My cursor kept going away and I couldn't even edit.
So, my problem is that at noon, my BG is like 120. Two hours after it goes up to 280, but then by dinner (5ish) it is back down to 100. My I:C ratio is set to 35. I am using U-500 Regular in my Animas insulin pump. I normally eat about 40 carbs for lunch Three days a week, I go to Cardiac Rehab for an hour. If I do the Rehab, then that makes my BG drop 100.
I am just trying to figure out what do with my settings because my body is doing weird in handling the carbs. Oh, My basal is set at .700 from noon to 5pm.

Do you eat lunch at noon?

I have to admit I know nothing about Regular. Is there a reason you aren't using one of the modern fast-acting insulins in your pump? I've heard that regular is very unpredictable. But aside from that, a ratio of 1:35 would mean you are very insulin sensitive. If you are routinely starting out before lunch at 120 and then ending up at 280, it sounds like you just aren't taking enough insulin. Can you try slowly bringing down that ratio and seeing how that works? Say start with 1:30 and try that for a couple days, etc.

In comparison to your bolus, your basal rates are quite "healthy" and that is why you are brought down so much before dinner. My suggestion? Start from scratch and do basal testing (Using Insulin by John Walsh explains how) or have your medical team help you to get your basals set right, then get your bolus adjusted by trial and error. Your numbers just don't sound right to me.

U-500 is a very CONCENTRATED insulin and is usually reserved for people who are very insulin resistant. Where Humalog or Novalog wouldn't even begin touching their blood glucose even at EXTREMELY high doses. I've know people taking over 80 units a day of Humalog and NOTHING. Still high blood glucose numbers.

I agree. My numbers don't sound right to me either. I am using regular because it is U-500. If I were to use Novolog U-100, I would be changing my pump every day. I have changed my I:C ratio down to 1:30 as of today. We're thinking the same thing. My CDE recently changed my basals. Now I have a tendency to go low in the middle of the night. So I've been tweaking that too. One night last week I dipped down to 35 around 4 in the morning. Took me 3 glasses of juice to get me up to 74. Scary. I've been pumping now since November 2008. I'm weird. What can I say?

yes I do.

Two thoughts -

You might need to increase your lunch time bolus and reduce the afternoon basal so your total dose stays constant but more insulin is working on those lunchtime carbs.

You might have to increase the time between your bolus and when you start eating so to the R has more chance to catch-up.


Oh, ok, so "one unit of insulin" (for 35 carbs) doesn't mean the same as it would with one of the fast acting insulin. But still, the proof is in the pudding that your ratios are too generous. Yeah, I would definitely tweak those basal rates as well! That IS scary!

I would agree with increase in waiting. I used Regular in my pump back when humalog wasn't around. I often had to wait 30-60 minutes, depending on what my starting BG was. Or at least start with the non-carbs, and postpone the carbs till end of meal.

Other things that helped with the post meal high:
taking a walk after the meal
Since Regular can last up to 6 hours, save some of your carbs from lunch, and have them as a snack 2-3 hrs after lunch.

Good ideas to consider. Thanks.

I agree with waiting to eat. Thanks.

That's me. 8)

I've been type 1 for 56 years this month. My body just does not want to cooperate sometimes. One week it will act like my pancreas is on a vacation. Other weeks, no matter what I do, it doesn't do what I want it to do. I even have to sometimes move my site because it doesn't want to be friendly in the spot I picked. U-500 is 5 times stronger than U-100. and 5 times more expensive. Thank God for insurance

I have to tell you, I am confused about your regime. Your basal is 0.7U/hr which is the same as 5*.7U/hr of U-100 insulin. That is about 84 units/day, not all that much. And your ICR is 30, corresponding to an ICR of 6 on U-100. That seems mildly insulin resistant. If you ate 120g/day, then you would need 20 more units a day. Shouldn't you get three days out of the pump? I am just confused.

But as to your current situation, the thing about U-500 is that it although it is concentrated Regular (R) insulin, it has an action profile similar to NPH, not U-100 R. This means that your insulin won't peak for 4-12 hours as compared with the 45min - 1hr for Novolog. This can cause exactly what you observed, you bolus for your meal, but your insulin doesn't act for hours and then when it does, your food is long gone causing a hypo. And your pump should be set for the proper duration of action (18-20 hrs) or you can get wicked stacking.

I have to be honest, given your description, you might do much better with few carbs. It is just almost impossible to do a carb bolus with U-500.

I don't understand the ins and outs of the insulin you use, but from what Brian-formerly-bsc and others have said it sound like it would be easier to just use whatever amount of fast acting insulin you require and either change your cartridge every day if that is what is needed, or just return to shots. At least you would have more accurate dosing and timing

I've often wondered how feasible it would be to use U-500 in a pump. Im not very familiar with it, just know a few who are on it, but they are Type 2's. It sounds complicated to me, I just wonder how many others out there might be pumping with it.

You are right with the math Brian. I do last 3 days with U-500. However, I use an Animas pump and the cartridge only holds 200. not 300, plus I also need to bolus for meals. Maybe you are on the right track about eating less carbs.

If I changed my cartridge every day, do you think I could get away with only changing the site every 3 days? The cost would be horrible to do a complete change every day.